Use of green (Opuntia megacantha) and red (Opuntia ficus-indica L.) cactus pear peels for developing a supplement rich in antioxidants, fiber, and Lactobacillus rhamnosus

Abstract

Cactus pear is an underused exotic fruit rich in health-promoting compounds with a high amount of peel in its composition. Thus, it is necessary to look for its application in the food industry. The aim of this study is to assess the proximal analysis, health-promoting compounds, sensory acceptance, and probiotic survival (Lactobacillus rhamnosus) of supplements based on red (RCPP) or green (GCPP) cactus pear peel. Both supplements presented a low moisture content (< 8%) and a high amount of dietary fiber (66-76%), with an adequate quantity of soluble dietary fiber (16.53 ± 1.84 and 19.78 ± 0.83%). Total phenolic compounds, betalains, and antioxidant capacity of the supplements were in the range of 392 to 543 mg GAE/100 g, 23 to 95 mg betalain/100 g, and 17 to 97 mmol Trolox/100 g, respectively, being always higher in RCPP, which was also better accepted by the consumers. After 5-h of gastrointestinal simulation, L. rhamnosus survival was about 5.79 x 106 CFU/mL for GCPP supplement, while 3.22 x 106 CFU/mL, were counted in RCPP supplement. Cactus pear by-products may be used for developing food supplements rich in fiber and probiotic bacteria widely demanded by the consumer.